Recently, active-matrix organic light-emitting diode (AMOLED) display devices have become more and more popular due to such advantages as ultrahigh contrast, very small thickness, very wide color gamut, wide viewing angle, very rapid response, and being capable of being curved at a very high curvature.
The AMOLED display device includes an OLED array substrate, which includes an OLED and a driving thin film transistor (TFT) for driving the OLED. A threshold voltage (Vth) drift may easily occur for the driving TFT, especially for an oxide TFT, so an external electrical compensation mechanism needs to be provided, so as to compensate for a threshold voltage of the TFT, thereby to improve a display effect of the AMOLED display device.
For the external electrical compensation mechanism, sufficient time and charging speed are required so as to achieve an optimum compensation effect. However, along with an increase in a size and a resolution of the display device, a resistance-capacitance (RC) loading of a sense line may increase remarkably. Hence, the sense line is charged at a small charging rate or insufficiently, and thereby it is impossible to achieve the desired compensation effect.